Ágel, V., Ludwig Eichinger, Hans-Werner Eroms, Peter Hellwig, Hans Heringer, and Hennig Lobin (eds.) 2003/6. Dependency and valency: An international handbook of contemporary research. Berlin: Walter de Gruyter.
Chiswell, Ian and Wilfrid Hodges 2007. Mathematical logic. Oxford: Oxford University Press.
Aho, Alfred et al. 2007. Compilers: Principles, techniques, & tools. Boston: Pearson/Addison Wesley.
